The present invention relates to a probe scanning device of a scanning type probe microscope or the like, particularly to a probe scanning device provided with a zoom function having excellent operational performance and capable of observing a surface of a sample with high accuracy without being influenced by heat or the like.
The applicant previously invented a probe scanning device having a zoom function as shown by FIG. 9 and applied for a patent (Japanese Patent Application No. Hei. 8-118015). A brief explanation will be given of the constitution and the operation of the probe scanning device as follows.
The first voice coil motor comprising a magnet 2 having a spindle portion 3, a movable member 4 wound with a coil 6 at its surrounding and a membrane 5, is attached to an upper inner portion of the cabinet 1. Further, the spindle 8 extending in z direction is fixed to the movable member 4. A displacement detector 9 is mounted to a lower end of the spindle 8 and a cantilever and a probe (tip) 10 are mounted to the displacement detector 9.
Meanwhile, the cabinet 1 is provided with a slender portion 14 projected to a sample chamber and a thick tube portion 15 connected thereto and an intermediate cylinder 13 is supported by the inner side of the thick tube portion 15 via a viscous body 17. Further, the spindle 8 is elastically supported by the first and the second spring 11 and 12 held by the intermediate cylinder. Electricity is conducted to a heating coil 16 to soften the viscous body 17 in coarse adjustment of the probe 10 in z direction.
Further, the second voice coil motor comprising a magnet 21 having a spindle portion 22, a movable member 23 wound with a coil 25 at its surroundings and a membrane 24, is attached to a side inner portion of the cabinet 1. A spindle 27 extending in x direction is attached to the movable member 23 and an open end of the spindle 27 is fixed to a portion 15a of the thick tube portion 15 via a slender wire 26. Further, although not illustrated, the third voice coil motor is attached in a direction different from the direction of the second voice coil motor by 90.degree. and similar to the above-described constitution and a slender wire and a spindle, both not illustrated, connect a movable member of the third voice coil motor and the thick tube portion 15. Further, by driving the second and the third voice coil motors, the probe 10 is scanned in x and y directions.
A sample base 31 is installed at a position opposed to the probe 10 and a sample 32 to be inspected or fabricated is mounted on the sample base 31. The sample base 31 is installed on a coarse adjustment x, y, and z stage 33.
A zooming device comprising a holder 34, a heating coil 35, a viscous body 36 put into the holder 34, a leaf spring 37 one end of which is fixed to the spindle 27 and other end of which is planted in the viscous body 36 and a clamp device 38, is installed at a vicinity of the magnet 21.
According to the zooming device, the viscous body 36 is softened by conducting electricity to the heating coil 35, the probe 10 is brought to above the location of the sample 32 by the above-described x and y scanning mechanism and thereafter, electricity conduction to the heating coil 35 is stopped by which the viscous body 36 is solidified. In this way, the spring constant of the leaf spring 37 is added to a synthesized lateral spring constant of the slender tube portion 14 and the thick tube portion 15 whereby the width of x scanning is restricted. Also in respect of y direction, the width of y scanning is restricted similarly by operating a zooming device, not illustrated, by which the zoom function can be realized. Incidentally, the details are described in the specification of patent application and an explanation thereof will be omitted.
However, there are following problems in the above-described device. (1) In operating the zoom function, electricity is conducted to the heating coil 35 whereby the viscous body 36 is softened, the probe 10 is brought to above the location of the sample 32 and thereafter, the electricity conduction to the heating coil 35 is stopped whereby the viscous body 36 is solidified. Therefore, a time period for softening the viscous body 36 by conducting electricity to the heating coil 35 and a time period required for solidifying the viscous body 36 by stopping electricity conduction to the heating coil 35, are considerable and the zooming operation cannot be carried out swiftly. (2) At normal time where the zoom function is not used, the viscous body 36 is softened by conducting electricity to the heating coil 35. At this moment, heat generated at the heating coil 35 is transferred to the scanner unit comprising the slender tube portion 14, the thick tube portion 15 and the like via the leaf spring 37 and the spindle 27 and members constituting the scanner unit are thermally expanded. Therefore, the probe 10 is moved and a distortion is caused in the detected image of the sample 32.
It is an object of the present invention to provide a probe scanning device eliminating the above-described problems of the conventional technology, having excellent operational performance and causing no distortion in a detected image of a sample.